The present invention relates to an electric system for vehicles, an electric system having plural electric loads for supplying electric power commonly to the plural electric loads, specifically to an electric power supplying apparatus, and intensive wiring apparatus for automotive vehicles.
As various kinds of electric equipment are usually used for riding vehicles, many system of electric power lines are used, for example, for supplying the electric power from the electric power apparatus such as batteries and electric power generator to the electric load.
In recent years, especially for automotive vehicles, many kinds of electric equipment are loaded and their numbers increases remarkably. As a result, there may be an unfavorable case in which an increase in the number of equipment wires in the vehicle gives some constraint problems in applying this kind system to the practical use.
For resolving this problem accompanied with the increase in the number of equipment systems, what is often used is a so-called "line concentration and wiring system" which is a controller having a communication function and an arithmetic function for controlling the individual electric load, in which the control signal for the individual electric load is obtained by numerical calculation and the control signal so calculated is transferred to the terminal apparatus connected to the controller through the communication lines, and thus, some electric loads connected to the terminal apparatus may be controlled.
With this controller, the number of lines required for transmitting the control signals can be reduced and resolve the problems accompanied with the increase in the number of equipment systems.
As for this kind of line concentration and wiring systems, for example, some systems in the prior art are disclosed in U.S. Pat. No. 4,771,382, U.S. Pat. No. 5,113,410, U.S. Pat. No. 4,855,896 and U.S. Pat. No. 5,438,506.
However, even in case of applying this kind of line concentration and wiring systems in the prior art, as the electric power to the individual electric load is supplied directly from the electric power line through the fusing fuse, the number of electric power lines is required so to be equal or larger than the number of electric loads. Therefore, in the prior art systems, the individual parts in the vehicle such as the ceiling and floor of the cabin are usually filled with many electric power lines.
In the conventional electric power supply system for the vehicles, what is generally used is a single-sided-earth electric power supply method, in which the electric power supply lines from the electric power supply assume that one part of the vehicle body is used as one side of the electric power supply line. Therefore, in case that any of electric power supply lines accidentally contacts the vehicle body, a short-circuit abnormality occurs.
In order to solve this short-circuit abnormality, in the prior art electric power supply systems for the vehicles, an independent fuse is installed for the individual electric load system, with which a designated electric load system may be protected by making the fuse melted when the electric power line gives a short-circuit and by separating the electric load system from the electric power supply.
In the prior art systems, when the fuse is melted in accordance with the electric circuit abnormality and then, the operation of the corresponding electric load is interrupted, there may be caused such a problem that the safety feature of the whole vehicle system and the comfort feature in driving the vehicle may be partially disabled or fully lost.